The assignee of the present invention manufactures and deploys spacecraft for, inter alia, communications and broadcast services from geostationary orbit. The present invention relates to a spacecraft radiator system including heat pipes and thermoelectric coolers. The thermoelectric coolers may also be referred to as Peltier devices.
Ordinarily, heat pipes are used to transfer and distribute thermal energy from heat sources such as operating electronic units to and across radiator panel surfaces from where it may be radiated into space. When the spacecraft is operating on-orbit, the radiator panels, generally, will be disposed in a North or South facing direction, because the North or South panels experience a solar radiation exposure that is relatively benign and stable compared to the East/West panels which experience significant diurnal cycles as the spacecraft orbits the Earth. As a result, conventional spacecraft designs frequently provide that North and South equipment panels are densely occupied by heat dissipating equipment such as traveling wave tube amplifiers and solid-state power amplifiers. U.S. Pat. No. 6,776,220, assigned to the assignee of the present invention, and hereby incorporated by reference into the present application, discloses known spacecraft radiator systems, including heat pipes.
Market demands for spacecraft offering higher power and more complex payloads challenge spacecraft designers to find mounting locations on which to dispose electronic components, including payload equipment. Although, as discussed above, conventional design practice is to preferentially mount payload equipment on North-South radiator panels, other locations must be found for at least some such equipment. For example, heat dissipating equipment may be disposed on transverse panels that are thermally coupled to the South radiator panels by way of the L-shaped heat pipes.
Some payload equipment, such as, for example, filters and low noise amplifiers (LNA's) dissipate relatively small amounts of heat, and may be disposed on spacecraft equipment panels that are not thermally coupled to North-South radiators. In such locations, however, the baseplate temperatures experience substantially diurnal variation and/or may be higher than desirable.
As a result, an improved approach to thermal control of spacecraft payload equipment is desirable.